It’s honestly the most grimy policy Tesla has. There should be two options
1) any software purchases stay with the VIN
2) any software purchase stays with the account.
I completely agree. Essentially what Tesla is doing here is pulling a bait and switch. They sell you a software upgrade for $2000 that increases your performance but don't make it clear that you loose it when you trade in your car. They don't refund your money, they remove it from the car so there's no increased value to the car and you don't get to keep it for your next car meaning they just suckered you out of $2000. Very slimy, IMO